The present invention relates generally to cutting tools and, more particularly, to cutting tools with cooling and/or lubricating arrangements.
Machining of metal with cutting tools generates very high heat. To preserve the cutting tool and reduce the risk of damage to the workpiece, it is desirable to provide a cooling or lubricating fluid at the point at which the machining operation occurs. Unfortunately, the space available for providing fluid conduits and other structures needed to introduce the fluid is often limited and may be used by structures necessary to clamp a replaceable cutting insert to a toolholder. Accordingly, it is desirable to provide a tool that facilitates introduction of cooling and/or lubricating fluid to the point at which the machining operation occurs. It is also desirable to provide such a tool that includes structure for securely and accurately positions a replaceable cutting insert relative to the toolholder and ensures that the accurate positioning is retained.
U.S. Pat. No. 4,848,198 describes one solution wherein a pivoting clamp for a replaceable cutting insert is provided with fluid flow conduits that are in flow communication with fluid flow conduits in a shank of the toolholder so that fluid can be introduced at a point above a working cutting edge of the insert. U.S. Patent App. Pub. No. US2011/0311323 describes another solution wherein a pivoting clamping arm has a portion that is received in an opening in a cutting insert and, when the clamping arm is clamped to a toolholder body, the clamping arm is caused to slide rearwardly, drawing the insert against abutment surfaces of a pocket of the toolholder body. However, because of the movement of the clamping arm relative to the toolholder body when clamping, a fluid conduit through the clamping arm leading to an opening near the working cutting edge must be connected to a source of fluid at a top of the clamping arm, which may interfere with certain cutting operations.
According to an aspect of the present invention, a toolholder comprises a clamp for clamping a cutting insert in an insert-receiving pocket of a toolholder body, the clamp comprising a clamp body having a clamp bottom surface, a post extending downwardly from the clamp bottom surface, and a protrusion comprising a clamp clamping surface extending downwardly from the clamp bottom surface, the toolholder body comprising a post hole for receiving the post, and a toolholder hole separate from the post hole, wherein the pocket has a bottom surface at least partially defined by a rear wall and a forward edge, and a fastener that extends through a clamp hole in the clamp body and into the toolholder hole, wherein a clamp fluid flow passage extends through the post and the clamp body to a point above the clamp bottom surface and the clamp clamping surface forms an angle of less than or equal to 70 degrees and greater than or equal to 20 degrees with a longitudinal axis of the post.
According to yet another aspect of the present invention, a tool is provided and comprises the toolholder noted above and a cutting insert disposed in the pocket, the cutting insert having a hole having a cutting insert clamping surface that is contacted by the clamp clamping surface. The clamp clamping surface and the cutting insert clamping surface are formed such that, as the clamp bottom surface is moved toward the bottom surface of the pocket when the post is in the post hole and the fastener is in the clamp hole and the toolholder hole, the cutting insert is urged against the bottom surface and the rear wall.